feat(cli): --quiet/--yes globals; echo resolved write target; gate non-local destructive writes (#243)

RFC-011 Decision 9. Writes echo their resolved target + access path to stderr (suppress with --quiet). Destructive writes (cleanup, overwrite load, branch delete) against a non-local scope require consent: --yes, a TTY prompt, or a hard refusal for non-TTY/--json runs. Local file:// writes unaffected.

crates/omnigraph-cli/tests/system_remote.rs

@@ -550,6 +550,8 @@ fn remote_branch_delete_removes_branch() {
             .arg("--config")
             .arg(&config)
             .arg("feature")
+            // Served target is non-local → destructive-confirm gate (RFC-011 D9).
+            .arg("--yes")
             .arg("--json"),
     ));
     assert_eq!(deleted["name"], "feature");